Contrary to what one might assume, rock climbing is not the opposite of rock tumbling, though it is still inadvisable to enjoy both activities concurrently. Learn to tumble upward with today's Groupon: for $30, you get two indoor rock-climbing packages at Hangar 18 (a $60 value). Each package includes all necessary equipment, a 60-minute rock-climbing lesson, and all-day climbing. This Groupon is redeemable at any of Hangar 18's three locations in Upland, Riverside, and South Bay. You can use this Groupon for two days of climbing for yourself or for one day of climbing with a friend.

With over 32,000 cumulative square feet of textured climbing terrain, world-class bouldering, and massive caves, Hangar 18's fake rocks are fit for kings who rule the wall with an iron fist made out of gold. During the 60-minute lesson, rock-groping newbies get schooled on every aspect of the climbing craft, including how to use the equipment, what types of knots to tie, proper belaying techniques, and essential communicative commands like "belay this.” The rock-gym walls are covered with textured products that mimic the conditions of real rocks (indentions, protrusions, overhangs, underhangs, cracks, and yetis included). Indoor climbing is a great way for someone to get started, or is a perfect after-work and climb-during-inclement-weather alternative for experienced climbers who want continuous practice.

The Riverside facility has one of the largest freestanding bouldering walls in the country and features 10 times as much roped climbing as any other gym in Riverside. The Upland location has a massive bouldering wall, two huge top-rope areas, an enormous cave, and a 40-foot-long roof climb across the ceiling, 40 feet off the ground. Conveniently located in the greater Los Angeles area, Hangar 18's South Bay indoor facility houses two massive, freestanding bouldering areas and a huge training section where you can work on rock-climbing fundamentals, or simply fantasize about the rock climbing you.